Very high performance loudspeaker enclosures

Abstract

Going inwardly from the outside, the walls of the housing comprise a multi-ply slab, one or more layers of elastomer coating, a plate of amorphous bitumen, and acoustic screens constituted by substantially contiguous parallel tubes which are filled with a solid material which is in the divided state and highly compacted, e.g. sand, or particles of graphite, or grains of silica. In addition, the enclosures include one or more blocks behind the loudspeakers and made of cellular foam with channels passing therethrough parallel to the axes of the loudspeakers.

I claim: 
     
       1. A loudspeaker enclosure comprising: top, bottom, front, rear and side wall members connected together to define said enclosure and an internal cavity therein, said wall members having internal and external surfaces;   at least one loudspeaker placed inside said internal cavity; and   an acoustic screen, lining the internal surface of at least one of the wall members in the internal cavity, having contiguous parallel tubes which are filled with solid dense particles that have been highly compacted into said tubes.   
     
     
       2. A loudspeaker enclosure according to claim 1, wherein said particles are taken for the group consisting of sand, graphite, and silica. 
     
     
       3. An enclosure according to claim 1, wherein the parallel tubes are interconnected by deformable and flexible connecting elements. 
     
     
       4. An enclosure according to claim 3, wherein said tubes and said connecting elements are made of a plastics material. 
     
     
       5. An enclosure according to claim 1, wherein said tubes are disposed horizontally. 
     
     
       6. An enclosure according to claim 1 further comprising at least one insulating block inside said internal cavity, said block being constituted by a cellular material having channels passing therethrough parallel to an axis of symmetry of the loudspeaker. 
     
     
       7. An enclosure according to claim 6, wherein said block comprises three glued-together vertical layers extending perpendicularly to said axis, said layers comprising a front layer and a back layer which are constituted by a high density open cell material having channels extending parallel to said axis, and an intermediate layer which is constituted by a very low density open cell cellular material. 
     
     
       8. An enclosure according to claim 7, wherein the channels of said front layer are offset to be between the channels of the back layer. 
     
     
       9. An enclosure according to claim 6, wherein said insulating block is made in a single piece and further comprises horizontal channels interposed between said channels extending parallel to said axis. 
     
     
       10. A loudspeaker enclosure according to claim 3, wherein said flexible connecting members are foldable so that the tubes can be brought close together. 
     
     
       11. A loudspeaker enclosure comprising: top, bottom, front, rear and side wall members connected together to define said enclosure and an internal cavity therein, said wall members having internal and external surfaces;   at least one loudspeaker placed inside said internal cavity, said loudspeaker having an axis of symmetry and a front and a back surface; and   an acoustic insulating block fixed to said back surface, said block made of a dense open cell material and provided with channels that extend through said block parallel to said axis.   
     
     
       12. A loudspeaker enclosure according to claim 11, wherein said cellular material is a polyurethene foam having a density of more than 100 kg/m 3 .